most will say patch from the back to give it strength and keep it from expanding. I think it's as simple as gluing another piece of vinyl to the back side around the spot. doesn't have to be same color, just something to give the tear some strength.

I'd seek out an upholstery shop. the couple bills they will charge would be peace of mind for me that it should be done right but with some patience and proper staple/nail guns could be done at home.